Process for solution mining of uranium ores

Abstract

In a process for the solution mining of a uranium ore formation using an aqueous alkaline carbonate leaching solution containing hydrogen peroxide as oxidant, the solution is passed through the ore formation in the presence of an alkylidene-1,1-diphosphonic acid. Such an acid has been found to be unique in its capability for stabilizing the peroxide against decomposition in the presence of the uranium ore.

We claim: 
     
       1. In a process for the solution mining of a uranium ore formation where an aqueous alkaline carbonate leaching solution having a pH of 7-10 and containing hydrogen peroxide as oxidant is passed through the ore formation to dissolve uranium from the formation therein and the solution is withdrawn from the ore formation enriched in uranium, the improvement comprising: passing the leaching solution through the ore formation, said leaching solution containing an alkylidene-1,1-diphosphonic acid having the structural formula: ##STR4## where X is --OH or --H, and R is an alkyl group of 1 to 5 carbon atoms wherein the diphosphonic acid is present at a concentration of at least 1 part per million by weight based on the weight of the leaching solution to stabilize the hydrogen peroxide.     
     
     
       2. The process of claim 1 wherein X is --OH and R is methyl. 
     
     
       3. The process of claim 2 wherein the diphosphonic acid concentration is in the range of 5-500 parts per million by weight. 
     
     
       4. The process of claim 3 wherein the alkaline carbonate leaching solution is an ammonium carbonate leaching solution.